1. Field of the Invention
This invention relates to methods and apparatus for finishing stucco walls, and more particularly to the apparatus useful for planning such stucco walls.
2. Prior Art
Stucco is a building finish that is applied to walls of buildings to make them weatherproof and to have a finished appearance. This polymer-based synthetic stucco prior art has been used primarily in the Southwest and south of the United States as an exterior siding applied to pre-manufactured rigid styrene board. My aforementioned co-pending Application covers a siding which is the spraying of a foam urethane on a wall. This foam urethane is spray-applied in preferably one pass, to provide a thickness of about xc2xe of an inch to 6 inches, for continuous bonding between the foam spray and the wall substrate. This monolithic single layer of foam as further described in my above-identified co-pending Patent Application, provides secure bonding to the wall substrate and eliminates subsequent water migration between the wall and that stucco foam application. A skin outer surface is developed on the foam spray. The foam spray may then be planed by a mechanical trimer.
Prior art devices, like that shown in U.S. Design Pat. No. 268,475 shows a handheld frame with an air motor powered twisted blade, for cutting the foam. Unfortunately, air powered motors may have problems with air pressure, and merely cutting the foam, without it""s removal, hinders the cutting and planning operation.
It is an object of the present invention to provide a motorized planer that overcomes the problems associated with prior art planers. It is a further object of the present invention, to provide a motorized planer that removes debris from the workplace. It is still a yet further object of the present invention, to provide a planer that is adjustable, clean, safe and efficient to operate on a sprayed-on urethane foam of the present invention.
The present invention involves a motorized planning apparatus for the resurfacing and flattening of an applied urethane foam on a wall substrate. The planning apparatus comprises an elongated housing having a sidewardly facing extension arranged off of each end thereof. Each sidewardly facing extension has an operator-supported handlebar adjustably arranged thereon. The planning apparatus is arranged to be carried and manipulated by an operator holding the handlebars, one handlebar in each hand. The handlebars are supported on the rear or the operator side of the housing. An electric motor is attached to a motor support extending off of the rear side of the housing. The electric motor is attached via a gear mechanism, to a drive shaft. The drive shaft is supported in a plurality of bearings, parallel to the rear side of the housing. An arrangement of shaft guards or shields encloses the shaft with respect to the housing. The distal end of the drive shaft has a drive pulley thereon.
An elongated foam cutter shaft is rotatably supported within the elongated housing. The elongated cutter shaft has a driven pulley in alignment with the drive pulley on the distal end of the drive shaft. The drive pulley and the drive driven pulley have a belt or link (therebetween so that rotation of the drive pulley rotates the driven pulley and the cutter shaft. The cutter shaft is hexagonal in cross sectional configuration. A plurality of elongated blades extends radially outwardly from the longitudinal axis of rotation of the cutter shaft. Each of the blades is held in radial alignment on the cutter shaft, by a locking strip arranged between adjacent blades. The locking strip is trapezoidal in cross section, so as to meet appropriately along its nonparallel edges, with the adjacent cutter blades. The locking strip is secured to the cutter shaft by a plurality of attachment bolts. Adjacent pairs of trapezoidal locking strips pinch the blades therebetween, and hold the blades closely to the shaft. The distalmost edge of each cutter blade has a plurality of spaced apart serrations thereon, the adjacent blades each having their serrations out of alignment with one another, so as to not effect the smooth cutting operation of the foam as the cutter rotates.
Each end of the housing also comprises a wall engaging lobe edge thereon. The cutter shaft is supported between the opposed lobe edges at each end of the housing. The contour of each lobe edge is such that as the housing is pivoted about its longitudinal axis between the lobe edges, this effects the arcuate pivoting of the cutter blades towards and away from the wall surface. This pivoting movement effects the amount (depth) of removal of the urethane foam from its roughened condition on the wall surface, as desired by the apparatus operator.
The urethane foam, as it is chipped away from the roughened surface against the wall, generates debris that is sucked up through a plenum chamber attached onto the upper side of the housing. The debris is drawn through a suction hose at each end of that housing. The split or paired suction hoses meet at a xe2x80x9cYxe2x80x9d junction, which is intended to be disposed behind the operator. The xe2x80x9cYxe2x80x9d junction has a single discharge conduit therefrom, which extends to a suction pump and collection tank, for receiving and containing a urethane foam debris as it is removed by the cutter blades and suctioned into the collection tank.
The operator controls the operation of the planer apparatus by a pair of triggers, one adjacent each handlebar at each end of the device.
Operation of the present vacuum planer apparatus permits a device operator to move the device down a foam sprayed surface from an upper portion thereof, flattening out that rough sprayed surface as it goes, the wall engaging lobe edges of the frame ride upon the intended surface, to effect a flattened resultant foam layer therebehind. The combination of the rotating flat blades scraping and cutting against the sprayed surface, and the split suction hose arrangement to withdraw debris, permits a flattened urethane foam wall to be fabricated with minimum inconvenience to the environment and to the builder.
The invention thus comprises a vacuum planer apparatus for the removal of rough debris from a foam sprayed wall to make that wall foam surface into a flat surface, comprising: an elongated housing having a first end and a second end; an arrangement of rotatable cutter blades mounted in the elongated housing; a drive motor arranged to empower the rotatable cutter blades; a support handle arranged on each end of the housing for pivotable control of the apparatus; and a debris suction conduit arranged at each end of the housing to pick up and remove foam scraped from the sprayed wall by the rotatable blades. The invention includes a xe2x80x9cYxe2x80x9d joint connecting each the suction conduit at each end of the housing, for ducting into a single discharge conduit, the rotatable cutter blades are mounted on a rotatable shaft, the rotatable shaft having a plurality of locking strips arranged adjacent each of the blades to secure each of the blades onto the rotatable shaft, the rotatable shaft may be hexagonal in cross-sectional shape, and the locking strips may be trapezoidal in cross-sectional shape for proper securement of the blades to the rotatable shaft. A collection tank may be arranged for capture of debris from the single discharge conduit. The blades have spaced apart serrations thereon for blade strength. The serrations on adjacent blades are out of alignment with one another for smoothness of the foam cutting and scrapping operation. The invention also includes a method of removing an uneven coating of sprayed urethane foam on a wall substrate to produce a smooth outer layer of foam on the wall, comprising the steps of: arranging an elongated housing with an elongated rotatable cutter blade device with a plurality of blades thereon, the device supported therein; empowering the rotatable cutter blade device to rotate by a motor attached to the housing; attaching an exhaust manifold to the housing to receive and duct away any foam debris generated by the rotatable blades; connecting a vacuum source to the exhaust manifold to effect removal of foam debris from the manifold; actuating the motor to rotate the cutter blades to cut and remove uneven foam from the foam spray on the wall; arranging the exhaust manifold into a pair of conduits to duct debris to the vacuum source; joining the pair of conduits into a common duct at a xe2x80x9cYxe2x80x9d junction to duct debris to the vacuum source; placing a plurality of spaced apart serrations on the blades to provide strength thereto; misaligning the serrations on adjacent blades to permit the blades to provide a smooth cut surface on the sprayed foam; securing the blades to the cutter blade device by a plurality of spaced apart elongated strips of trapezoidal cross-sectional shape.